Spatiotemporal electric field distribution in an EHV substation in view of occupational exposure

Abstract

With the increase in the transmission voltage levels, the effect of non-ionizing radiation (NIR) becomes a major concern. The International Commission on Non-Ionizing Radiation (ICNIRP) provides the guidelines for protection against NIR. It suggests the reference electric field (e-field) value of 10 kV/m for occupational exposure and 5 kV/m for general public exposure for the substation. In view of this, e-field prevailing in a 765 kV generating substation is studied in the present work to assess the spatiotemporal distribution using charge simulation method (CSM) based model. This should give a feel of the possible threat posed by these fields to the working personal due to NIR. The upcoming EHV substation in central India is considered with its bays, transmission lines, buses, and ground wires. The instantaneous values of e-field are computed at different instances over the 50 Hz voltage cycle, at 2 m height above the ground plane over the entire substation arena. The demo of spatiotemporal variation of e-field computed at different instants of time over a cycle using simulating charges taken from the real-number-field will be presented and discussed during the presentation. This would result in a time-space changing e-field-force, and give a feel of creation of churning of air and electric wind. This will have much higher significance at the heights were conductors are placed where the e-fields are higher. It is also shown that because of spatiotemporal variation of e-field, the rms value of e-field can be easily obtained using simulating charges taken from complex-number-field which is of significance from the point of view of ICNIRP guidelines.